You didn't made a mistake, IMHO.

Nobody made a mistake.

There was just a mistmatch between your unvoiced assumptions and those of other people posting here, so all of you were really just starting from different points and hence going in different directions.

I suppose many downvoters might have assumed you were purposefully taking a specifically literal interpretation of "anonymous" in this context for the purpose of defending the University whilst I myself just went with it being a perfectly valid explanation until proven otherwise that you're just a more literal person than most.

This is why I went for writting a post which I believed would provide some clarity rather than downvoting your posts.

As I see it your points were valid for an interpretation that the University and the article used "anonymous" in the most honest of ways (meaning, "unknown to others") and other posters pointers were valid for an interpretation that the University and the article used "anonymous" in a deceitful way that didn't match the dictionary definition but instead meant "unknown to the general public", something for which the correct word is "undisclosed".